1. Field of the Invention
The present invention relates to magnetic tape drives, and more particularly to a magnetic tape drive in which tape on a supply reel contained within a cartridge is automatically threaded onto a take-up reel using vacuum.
2. History of the Prior Art
It is known to provide a magnetic tape drive in which tape wound on a supply reel is automatically threaded onto a take-up reel using vacuum. An example of such a tap drive is provided by U.S. Pat. No. 4,243,186 of Peter et al. In the Peter et al patent tape from a supply reel is drawn by a vacuum-created air flow into and through a generally enclosed elongated flowpath extending between the supply reel and a take-up reel onto which the tape is eventually wound. The vacuum is provided by a vacuum source which is coupled to the flowpath via apertures in the hub mounting the take-up reel. The supply reel which is removable from the magnetic tape drive is installed by insertion through a slot in the front of the tape drive and disposition over a hub which includes reel centering and locking arrangements.
Other examples of magnetic tape drives in which magnetic tape wound upon a supply reel is automatically threaded onto a take-up reel using vacuum or other means for creating an air flow are provided by U.S. Pat. Nos. 3,863,863 of Ende, 3,127,120 of Selsted et al, 3,134,527 of Willis, 3,910,526 of Mosciatti and 3,795,371 of Tolini et al. The Selsted et al and Willis patents are like the Peter et al patent in that the magnetic tape drives disclosed therein provide automatic threading of the tape from the supply reel to the take-up reel exclusively by vacuum means.
Magnetic tape drives in which the supply reel is mounted within a cartridge removable from the tape drive have recently become very popular for various applications. In those applications it is highly advantageous to have the supply reel enclosed within a cartridge so that the cartridge as a single, integral unit can be easily installed in and removed from the magnetic tape drive. The cartridge encloses and protects the tape in addition to facilitating the use of different reels of tape within the tape drive. Within such cartridge tape drives it is highly desirable to provide automatic threading of the tape wound upon the supply reel within the cartridge. The tape is automatically threaded past the magnetic head assembly and onto the take-up reel mounted within the magnetic tape drive.
Cartridge tape drives are known in which the tape from the supply reel within the cartridge is automatically threaded using various mechanical arrangements. Such mechanical arrangements tend to be complex and expensive and in some cases of questionable reliability. Most such mechanical arrangements require that the leading end of the tape have some sort of mechanical element or leader attached thereto to enable the tape to be pulled from the cartridge and automatically fed to the take-up reel. Uniform winding of the tape onto the take-up reel is made difficult where such a mechanical element or leader is present.
Accordingly, it would be desirable to provide a cartridge tape drive in which automatic threading of the tape is accomplished by vacuum or other air flow creating means and without the need for a leader or other mechanical element on the tape. However, the prior art noted above which utilizes vacuum and similar automatic threading arrangements does not involve cartridges and therefore does not address the problem of designing a tape drive which accommodates tape cartridges and which also facilitates automatic threading by vacuum or similar means. In all of the patents noted above, the supply reel is placed on a supply reel hub by hand rather than having the supply reel contained within a cartridge with the cartridge being installed in the tape drive.
Accordingly, it would be desirable to provide a cartridge tape drive in which automatic threading is accomplished using a vacuum. It would furthermore be desirable to provide an improved tape cartridge for use in automatic threading operations using vacuum or other air flow producing means.